Failing to show the appropriate amount as taxable usually means failure to enter into TurboTax the year-end value in traditional IRAs that needs to appear on line 6 of Form 8606 (or on Worksheet 1-1 from IRS Pub 590-B that TurboTax uses when there are also nondeductible traditional IRA contributions made for the year). Be sure to click the Continue button on the page that lists the Forms 1099-R that you have entered and TurboTax will ask you to enter the year-end value in your traditional IRAs. You'll see the taxable amount of the Roth conversion determined on Form 8606 Part I and Part II. The amount on line 18 will be include on Form 1040 line 4b.
